Power transfer device for a rolling door operator

ABSTRACT

A power transfer device for a fire door operator having a pair of drive gears includes a bridge gear box having a drive shaft suitable for being coupled to an external drive. An idle spur gear is fixed to the drive shaft. A pair of spur gears are coupled to the idle spur gear to rotate in response to rotations of the idle spur gear. Spur gear shafts are coupled to the spur gears and arranged to be coupled to the drive gears of the operator so that rotation of the drive shaft by an external drive is translated to simultaneous rotations of the drive gears of the operator.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.16/741,073 filed on Jan. 13, 2020 which is incorporated as if fully setforth herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to rolling doors and, morespecifically, a power transfer device for a rolling door operator.

2. Description of the Prior Art

Roller shutter doors have been known for some time and are used in avariety of applications. They include such categories as: rollinggrille; storm doors; fire and smoke doors; air-leakage doors, countershutters; and, the like. What they have in common is a construction thatallows them to be rolled up onto a drum or tube when in the openposition; or, to be unreeled from the drum when the door is beinglowered. Theses doors are typically used in commercial establishments toseal or close off large doorways, or bays, and can be operatedelectrically, manually, or both.

The methods and systems for driving the doors into an upward or downwardposition, during normal or emergency operation, have evolved over timefrom simple pull down doors of a kind used in residential garages, tomore technologically advanced electric drive systems with timers, manualover-rides, and diverse safety features.

Generally, commercial or large capacity fire doors were driven byelectric motors to open or close the door. However, when a fireoccurred, these mechanisms would disengage the motor from the fire doorand allow the door to close under the pressure exerted by an auxiliaryspring activated by mechanical means or from a counterbalance. Thesemechanical means included pendulums, oscillating governors, frictiondiscs, ratchets, etc. These mechanical devices tended to be unreliablebecause of jamming or other malfunctions caused by the motion of thedoor. One early mechanism that attempted to address this problem wasdescribed in U.S. Pat. No. 5,203,392 for a Mechanism For Controlling TheRaising And Lowering Of A Door, issued Apr. 20, 1993 to Shea(hereinafter referred to as “Shea”).

In Shea, there is disclosed a mechanism for controlling the opening andclosing of a door such as a fire door. The mechanism controls the speedof the door when it drops under the force of gravity; and, can beelectrically, or manually, operated. The problem that Shea wasattempting to address was the need for a fire door mechanism thatregulates the raising and lowering of the door while effectivelycontrolling the door's movement without the need of springs or similarmechanical means. The speed of the door's drop was under control of acentrifugal governor employing brake shoes.

Other prior art has addressed the need for testing the speed and effectsof the door's drop during non-emergency uses. U.S. Pat. No. 5,482,103for a Door Apparatus With Release Assembly, issued Jan. 9, 1996 toBurgess et al. (hereinafter referred to as “Burgess”) teaches the use ofa counterweight to offset the weight of the roller door and a reducingweight to reduce the weight of the counterweight. The assembly of thedoor allows the use of a standard governor to control downward speed.This use of reduced weight and the resultant reduced stress on the doorallows the mechanism to use parts that are reduced in size and weight.

After the disclosures of Shea and Burgess, came the teachings of U.S.Pat. No. 5,924,949 for an Apparatus For Driving A Roller Shutter Door,issued Jul. 20, 1999 to Fan (hereinafter referred to as “Fan”). Fanteaches a driving mechanism for roller shutter doors that can beadjusted from outside of the apparatus so as to accommodate doors ofdifferent heights. The advantage of Fan is that the mechanism, if eithermoved from a door of one height to a door of a differing height, or ifthe door is not of the height for which the factory settings apply, doesnot have to be disassembled for adjustments. Rather, the adjustablecontrol means is disposed within the stationary housing of theapparatus, and extends from within the apparatus to a point outsidewhere it can be manipulated or adjusted as required. And, while Fanaddresses a legitimate need, it still leaves unanswered the need toallow the door to move freely into an open position while under controlof a governor.

Further improvements to the drive mechanism are taught in U.S. Pat. No.6,530,863 for a Door Operator Unit, issued Mar. 11, 2003 to Balli et al.(hereinafter referred to as “Balli”). In Balli, an improved powertransmission mechanism which works between the drive motor and theoperator output shaft is disclosed. The operator unit is adapted toreverse the positions of a manual operator drive and a releasemechanism. The advantage provided by Balli is the ability to interchangethe operator unit components depending upon the door configuration orapplication. Thus, the drive mechanism can be established as either aright side or a left side mount. Balli still leaves the question of doorcontrol after rebounding, or the issue of timer adjusted openings andclosings to be addressed.

The evolution of the rollup door and its drivers and safety mechanismshas continued with the disclosures of U.S. Pat. No. 7,261,139 for aManual Operating Mechanism For Upward Acting Door, issued Aug. 28, 2007to Varley et al. Varley teaches a mechanism that addresses thedifficulty of operating a roll-up door manually in those cases where thedrive motor is mounted in an assembly that is beyond the easy reach ofthe user. The mechanism of Varley includes a manual brake release thatis foot actuated by a person using an elongated crank handle to manuallymove the door from an open to closed position or vice versa. A problemleft unanswered by Varley is how an operator, under the stress of anemergency, can efficiently disengage the motor drive.

What is not appreciated by the prior art is the need to provide a methodand apparatus for controlling the drop of the door (or curtain as thecase may be) that incorporates each of the successes of the prior artwhile minimizing the problems. One important issue not addressed by theprior art, is that the drop of the door should be controlled by amechanical centrifugal governor such that the door does not “bounce”after it arrives in the full open position. While in a closed position,the curtain or door must be able to maintain its locked position unlessthe door or curtain is manually released through the use of a manuallever and/or an electrical switch. The use of a timer to allow the doorto re-open at least part-way, and then close after a specific timeinterval during an emergency, would provide a safety that is currentlylacking in the art.

Accordingly, there is a need for an improved method and apparatus thatwill supply multiple safety features in the event of an emergency whileproviding for more efficient operation of the door during normal use.

In U.S. Pat. No. 8,069,896, assigned to the applicant of the presentinvention, a method and apparatus are disclosed for driving a rollershutter assembly that includes a gear box provided with a gear havingexternal teeth along the outer periphery engageable with two one waybearings mounted on a rocker arm to selectively allow the gear to rotatein one or the other direction. This requires a rocker arm with matingopposing one way bearings. Also, included are limited switches that aredirectly coupled to a hub attached to the shaft of the rolling door.

However, the limit switches are mounted inside the motor operatorhousing and require disassembly of the operator to make any changes oradjustments.

U.S. Pat. No. 7,878,230 discloses a door release mechanism that it usesan external drop arm to control a governor shaft secured to the sun gearof a planetary gear system. The release of the drop arm from engagementwith a rotatable plate secured to the sun gear allows the shaft tofreely rotate. This, however, requires an externally mounted drop armand an externally mounted plate that can rotate at a relatively highspeed, both the drop arm and plate being exposed to contaminants andforeign objects that can interfere with their operation.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a power transfer device foran operator for a rolling fire door that does not have the disadvantagesinherent in prior art devices of this type.

It is another object of the invention to provide a power transfer devicefor a rolling door that is easy and convenient to operate.

It is still another object of the invention to provide a power transferdevice for a fire door operator for a rolling door that is simple inconstruction and inexpensive to manufacture.

It is yet another object of the invention to provide a power transferdevice for a fire door operator for rolling doors that can be driven bya number of different drives, including hand chain assemblies, anoperator motor that is mounted on the operator or an external motor thatdrives the operator by means of a chain drive or the like.

It is a further object of the invention to provide a universal fire dooroperator that can control the speed of a dropping rolling door with anumber of different braking mechanisms, including centrifugal governor,a viscous governor, an electromagnetic clutch braking and the like.

In order to achieve the above objects, as well as others that willbecome evident hereinafter, a power transfer device for a fire dooroperator having a pair of drive gears comprises a bridge gear box havinga drive shaft suitable for being coupled to an external drive. An idlespur gear is fixed to said drive shaft. A pair of spur gears are coupledto said idle spur gear to rotate in response to rotations of said idlespur gear. Spur gear shafts are coupled to said spur gears and arrangedto be coupled to the drive gears of the operator. In this way rotationof said drive shaft by an external drive is translated to simultaneousrotations of the drive gears of the operator.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions are in reference to the accompanying drawingsin which the same or similar parts are referenced by the same numeralsthroughout the several drawings, and wherein:

FIG. 1 is a side elevational view of one embodiment of the presentinvention illustrating a hand operated chain assembly to manuallyoperate the operator to raise and lower a rolling door;

FIG. 2 is an exploded view of the operator shown in FIG. 1;

FIG. 3 is an exploded perspective view of the internal components of theoperator shown in FIGS. 1 and 2 as viewed from the housing side;

FIG. 4 is similar to FIG. 3 shown with the drive gears and the sun gearcoupled to each other;

FIG. 5 is an exploded perspective view of the device as shown in FIG. 4,as viewed from the direction of the carrier and hub that receive and areconnected to the shaft of the rolling door;

FIG. 6 is a side elevational view of an alternate embodiment of theoperator utilizing twin DC motors to drive the operator;

FIG. 7 is an exploded view of the operator shown in FIG. 6;

FIG. 8 is an exploded view of a bridge gear box used in conjunction withthe operator shown in FIG. 1;

FIG. 9 is a side elevational view of a still further embodiment of theinvention driven by an external motor;

FIG. 10 is an exploded view of the operator shown in FIG. 9;

FIG. 11 is an exploded view, in elevation of the operator shown in FIG.4.

DETAILED DESCRIPTION

Referring now to the figures, in which identical or similar parts aredesignated by the same reference numerals throughout, and firstreferring to FIG. 1, an operator in accordance with the presentinvention is generally designated by the reference numeral 10.

The operator 10 is mounted on a side drive bracket plate 12 secured to avertical channel or wall angles 14. A rolling door 16 shown in FIG. 2 istypically mounted on a barrel assembly 18 shown in FIG. 3 that definesan axis A and is operated by the controller 10. The fire door operator10 is used to control a rolling door that can be raised when rolled ontothe barrel assembly 18 when the shaft 18 a rotates in a first directionand lowered when the shaft rotates in an opposing direction, as is knownin the art. The shaft 18 a can be any one of a number of differentdiameters depending on the size and the weight of the rolling door.

The operator 10 includes a generally cup-shaped housing 20 has interiorspace 20 a as shown in FIG. 5, mounting flanges 20 b and a centralopening 20 c as shown in FIG. 4. The housing forms a peripheral annularwall 20 d, a flange 20 e with an opening is formed along the peripheryas shown, for example, in FIG. 4. While one axial end of the housing 20is open the other end is substantially closed by a wall 20 f formed withat least one lateral opening 20 g from the axis A offset, two openingsbeing shown in FIG. 4. The axis A is coextensive with the shaft 18 awhen assembled and mounted on the shaft.

Referring to FIGS. 4 and 5, the operator is provided with a main outergear in the form of an annular ring mounted within the housing 20 forrotation about the axis A and is formed with exterior teeth 22 a andradially inwardly spaced interior teeth 22 b. Planet gears 24 are meshedwith the interior teeth 22 b and a sun gear 26 is meshed with the planetgears 24 for rotation about the axis A.

A carrier 32 in the form of a circular plate or disk is fixedly attachedto a hub 34 in any conventional manner and shares rotations with thecarrier 32. The carrier 32 is also secured to the planetary gears 24, asindicated. The hub 34 can be secured to the shaft 18 a in any suitableor conventional manner. The hub 34 includes a mounting plate 34 aattachable to the carrier 32 and an annular extension 34 b formed at theradial end opposite to the mounting plate with external teeth 34 c. Akeyway 34 d is shown for securing the shaft 18 a to the hub 34 forsharing rotations therewith.

A locking mechanism 36 is provided for normally locking the main outeror ring gear 22 in relation to the housing 20. The locking device, inthe example shown, is a rocking arm 36 positioned in proximity to theexterior teeth 22 a of the annular ring 22 and provided with lockingteeth 36 a configured to mesh with the outer or exterior teeth 22 a ofthe main or ring gear 22. In a locking position, the teeth 36 a engagethe teeth 22 a and prevent the ring gear 22 from rotating about the axisA. The rocker arm 36 a can be manually or electromechanically urged fromits normal biased locking position to move the locking teeth 36 a out ofengagement with the exterior teeth 22 a thereby releasing the outer orgear ring 22. The rocker arm 36 can be controlled manually by a stringor pull chain attached to a loop 36 b shown in FIG. 4. However, therocker arm 35 can also be moved from its normally biased position by anyknown actuating devices, such as salenoids, step motors or the like.When the main outer or ring gear 22 is released it can freely rotatewithin the housing 20 and is not exposed to contaminants or exteriorobjects that can potentially interfere with that movement.

One of the features of the invention is the use of a direct drive limitswitch 38 shown, for example, in FIG. 5. As shown, the direct drivelimit switch assembly 38 is connected by means of a reduction gear set40 that includes gears 40 a-40 c, the gear 40 c being directly coupledto the outer or exterior teeth 34 c of the hub 34. Rotation of the hub34 is directly indicative of the rotational speed of the barrel assemblyor shaft 18 a that, therefore, the speed at which the rolling door orcurtain 16 is dropping. The direct drive limit switch 38 is alsoindicative of the position of the rolling door 16. When the door reachesits upper position or its lower position the drive limit switch 38generates electrical signals that can be used to stop any motor drivefrom further attempting to raise a door any higher or dropping it anylower. The limit switch assembly is also discussed in U.S. Pat. No.8,069,896. An important feature of the invention is provision of a slotor opening 20 e (FIG. 4) in the housing 20 through which the gear 40 aof the direct drive limit switch can extend so that at least a portionof this gear 40 a projects below or outside of the housing 20. Thisallows the direct drive limit switch 38 to be mounted outside of thehousing 20 while still maintaining precise information of the movementsof the sun gear 26 c and the position of the rolling door.

An opening 26 h is provided in the wall 26 d for providing access to theouter teeth 22 a of the ring gear 22 when the rocker arm 36 is mountedon the housing 20. Similarly, an opening 26 i is provided on the annularwall 20 d to enable the gear train 40 to engage the direct drive limitswitch assembly 38 which is likewise mounted exteriorly of the housing20.

When the rocker arm 36 is moved from a locking position in which theteeth 36 a engage the teeth 22 a on the ring gear to an unlockingposition these teeth disengage from each other. The ring gear is freedto rotate as is the sun gear 26 as well as the hub 34 and the carrier32. This allows the shaft 18 a to freely rotate and the door rolled upon the barrel assembly to drop under its own weight. However, when thedoor starts to accelerate and pick up speed the dropping speed must beregulated or controlled to avoid excessive speeds and potential hazards.Other known release devices can be used such as fusible links,electromechanical release devices such as solenoids and motor controlledrelease devices.

In FIGS. 1 and 2 such control over the rotational speed of the hub 34and the carrier 32 is provided by features shown in FIGS. 1 and 2 andFIGS. 3-5. Such speed control is provided by a governor 42 that includesa centrifugal mechanism 42 a, a shaft 42 b and a gear 42 c that isalways engaged with the outer teeth 22 a of the ring gear 22. The shaft42 b extends through an opening in the flange 20 e formed on the housing20. Other braking mechanisms can be used, such as an electromagneticclutch 60 coupled by means of a chain 62 to a sprocket 64 mounted on abracket 66. The sprocket 64 is coupled by means of a bearing 70 to agear 72 that is always engaged with the outer teeth 22 a of the ringgear. When the ring gear starts to accelerate excessively upon releaseby the rocker arm 36 the electromagnetic clutch 60 detects the speed andcreates counter force that resists further increases in the speed of thering gear. Braking devices, including viscous governors and otherbraking devices well known to those in the art can be used withdifferent degrees of advantage.

Drives for raising and lowering the door are applied via the sun gear26, as indicated, through the outer teeth 26 c that mesh with the drivegears 30. Other known ways for applying rotational forces to the sungear cam be used and contemplated.

In FIGS. 1 and 2 drive is provided by a hand chain assembly 28, thedetails of which are more fully described in U.S. Pending patentapplication Ser. No. 16/584,330 which is incorporated as if fully setforth herein. For this purpose, two openings 26 g are provided in thehousing 20 as shown in FIG. 4. The chain 46, driven by the hand chainassembly 48, is coupled to sprocket gear 52 to a bridge gear box 50,more fully described in connection with FIG. 8. Bridge gear box 50includes a housing 50 a having a cover 50 b. A drive shaft 50 c iscoupled to an idle spur gear 50 d meshed with two spur gears 50 e and 50f as shown. The spur gears 50 e and 50 f are coupled to spur gear shafts50 g and 50 h, respectively, mounted on bearings 50 i and 50 j. Thedrive shaft 50 c and gear sprocket 52 are also mounted on a drive shaftbearing 54. As will be clear, rotation of the gear sprocket 52 and thedrive shaft 50 c transmits rotational torque by means of the spur gear50 d to the spur gears 50 e and 50 f thereby rotating spur gear shafts50 g and 50 h. These are coupled, in turn, to drive gears 30 that arecoupled to and transmit rotational forces to the sun gear by way of theouter teeth 26 c.

Instead of hand chain assembly 48 any other suitable drive can be used.For example, referring to FIGS. 6 and 7, twin DC motors 44 a, 44 b eachcoupled to a right angle degree gear box 44 c, 44 d, respectively, eachof the gear boxes has a shaft that extends through the openings 26 g ofthe housing and coupled to the drive gears 30 as with the gear shafts 50g, 50 h. Other devices can be used such as direct drive chain hoists,reduced drive chain hoists and compound reduction chain hoists.

In a similar manner, referring to FIGS. 9 and 10, an external motor 56can be used to drive the chain 46. The motor 56 is electrically coupledto the limit switch assembly 38 to prevent continued rotation of themotor 56 when the limit switches indicate that the door has reached alower most or an upper most position and, the bridge gear box 50 can beused to transmit the drive power of the motor 56 to the drive gears 30and, therefore, to the sun gear 26. The motor 56 can be of a third partyoperator 74, so that the operator of the present invention can be usedwith third party operators in the aforementioned drive mechanism.

It will be appreciated that the use of a ring gear 22 provided withexterior or outer teeth 22 a and inner teeth 22 b in the planetary gearsystem 10 render the operator extremely versatile and, in effect,universal in that it can be adapted to work with almost any drives andbraking systems. Additionally, by utilizing a direct drive gear set 40coupled to the hub 34, therefore, also to the shaft attached to the hubthe direct drive limit switch assembly can be mounted outside of thehousing. This facilitates servicing it and adjustments of the directdrive limit assembly without requiring disassembly of the entire unit.

While the invention has been shown and described with reference tocertain embodiments thereof, it will be understood by those skilled inthe art that various changes in form and detail may be made thereinwithout departing from the spirit and scope of the invention as definedby the appended claims and their equivalents.

1. A power transfer device for a fire door operator having a pair of drive gears comprising a bridge gear box having a drive shaft suitable for being coupled to an external drive; an idle spur gear fixed to said drive shaft; a pair of spur gears coupled to said idle spur gear to rotate in response to rotations of said idle spur gear; and spur gear shafts coupled to said spur gears and arranged to be coupled to the drive gears of the operator, whereby rotation of said drive shaft by an external drive is translated to simultaneous rotations of the drive gears of the operator.
 2. A power transfer device as defined in claim 1, in combination with a fire door operator.
 3. A power transfer device as defined in claim 2, wherein said fire door operator is coupled to a rolling door that can be raised when rolled onto a generally horizontal shaft when the shaft rotates in a first direction and lowered when the shaft rotates in an opposing direction, said operator comprising a planetary gear system; a carrier secured to said planetary gear system adapted to be coupled to the rolling door shaft; and drive means coupled to said bridge gear box for selectively driving said planetary gear system to transmit rotational power to the rolling door shaft.
 4. A power transfer device as defined in claim 3, wherein said drive means comprises a hand-operated chain drive coupled to said planetary gear system.
 5. A power transfer device as defined in claim 3, wherein said drive means comprises an exterior motor coupled to said planetary gear system.
 6. A power transfer device as defined in claim 5, wherein said exterior motor is coupled by means of a drive shaft engaged with said planetary gear system; and a sprocket fixedly mounted on said drive shaft for coupling said drive shaft to said exterior motor.
 7. A power transfer device as defined in claim 6, wherein said bridge gear box couples said drive shaft to two spur gears for driving said operator drive gears. 